Pinhole grinding or honing tool



April 4, 1933- w. P. ROBERTS l 1,903,343

I PINHOLE GRINDING OR HONING TOOL Filed Feb. 17, 19:52`

akamu, v

bronze or alloy metals.

adjustment .730 to .870, another Patented Apr. 4, 1933Y UNITED STATESPATENT OFFICE WILLIAM nur. aanname, or emxsnuae, INDIANA rmnoin eaINDmGon noNING moor.

Application 'led February 17, 1982. Serial N0. 593,608..

My invention relates-to tools for grinding and polishing the walls ofpiston pin-holes, bearing bushings and other small diameter apertures incast iron, steel, alumlnum,

Heretofore tools have been provided for I the purpose but their use hasbeen limited toa narrow range of adjustments requiring several tools tomake up a set to fit the 0 entire range of pin holes from the minimumfor truck sizesranging in adjustment from 1.130 to 1.530. My inventionhas forone of its objects to provide an improved honmg tool of suchdesignand construction thatV one tool will cover the whole range ofsizes now covered by the sets of three or four tools, thus reducing thenumber of tools whichthe mechanic must have 'in his shop in order torender satisfactory service to his customers and also reducing theinvested expense greatly.

A further ob'ect is to provide a hone byl the use of whic the pin holescan be honed from standard to the next oversize in but a few seconds,thereby greatly decreaslng the time-labor charge on a given job.

Further, it is an object to provide a pin hole grinder which may be usedon spring bushings, shackle and axle bushings, either straight ortapered.

tively hold the adjused relation of its parts against slipping orloosening up` while in use. v

Further, it is an object to provide a tool such as above indicated sovdesigned that it may be adjusted while in position in the hole.

Other objects will in part be obvious and in part be pointed outhereinafter.

To the attainment of the aforesaid objects and ends, the invention stillfurther resides which. will be irst fully described in the followingdetailed description, then be particularly pointed out in the appendedclaims, reference being had to the accompanying drawing, in which:

Figure 1 is a perspective view of the tool in use, a piston being shownin sectional perspective.

.in the novel details of construction, combi- 5 nation and arrangementof parts, all of Figure 2 is an elevation of the tool, one 01EA 35 theabrading elements being shown in vertical section.

Figure 3 is an enlarged detail vertical lon.- gitudinal section of oneend of the tool.

Figurefl is a cross section on the line 4 4 70 of Figure 3.

Figure 5 is'a detail perspective view of one of the emery cloth abrasiveelements.

Figure 6 is a detail perspective view of one of the stone abrasiveelements.

Figure 7 is a longitudinal section showin ofv the tool may be adjustedfor tapered o es.

In the drawing in which like numerals of reference indicate like partsin all of the figures, 1 represents a mandrel havin flattened portions 2and 3 spaced a suitab e distance, the mandrel having threaded portions 4and 5 beyond the flattened ortions 2 and 3.

6 is the end of the man rel which is insertible in the chuck of thedriving engine. The driving engine may be any suitable one for thepurpose as for instance a handle o erated or a power operated drilldrive. e flattened portion 2 which is adjacent the end of the mandrelthat is remote from the end 6 has a longitudinal slot 7 through whichone of the link link pivot pm 8 passes through a round hole in theflattened portion 3.

The mandrel 1 is longitudinally bored as at 9 to provide a concavity forthe adjusting screw pin 11, the bore being .threaded as at 10 tocooperate with the threaded portion 13 of the adjusting screw pin 11.lThe adjusting pivot pins 8 passes. Theother v screw pin 11 has anannular groove 12 to receive the link pivot pin 8 that passes throughthe slot 7. By placing a screw driver in the kerf 14 of the adjustingscrew pin 11 it may be turned to advance or retract it and thereby movethe adjacent link pivot pin back and forth along the slot 7 to increaseor diminish the distance between the two pivot pins 8/accordingly for apurpose hereinafter more clearly understood.

15 is the abrasive element spreader abutment which may be a knurled diskor a nut, and 16 designates a correspondingly formed abrasive elementcontracting abutment, the abutments 15 and 16 being threaded on thethreaded portions 5 and 4 respectively.

17 designates the abrasive element carrier bars of which there are two.These bars are of curved cross section approximately to conform to thecurvature of the mandrel so that when they are in the contractedposition they will lie in proximity to the mandrel. The longitudinaledges 18 of the bars 17 are somewhat reduced in thickness to fit theU-shaped attaching strips 28 which carry the abrasive elements 22. Thebars 17 have suitable slots 19 into which the links 21 project, therebeing link pins 2O provided for pivotally connecting the links 21 to thebars The metal edge strips 23 are bent back upon themselves as at 24 toform a channel in which the edges of the abrasive element (emery cloth)is held by punchings 25 or other suitable means so that when the strips23 are in engagement with the edges 18 the abrasive element 22 will betightly fitted to the outer curvatures of the abrasive carrier bars 17.

While an emery cloth abrasive may be used on each carrier bar Ipreferably provide one of the carrier bars with a stone abrasive element30 mounted on a rigid backing 28 of metal having its ends turned underto form grooves 29 tov fit the edges 18 of the bars 17.

26 and 27 designate recesses in the flattened portions of the mandrel 1to receive the pivot pins 20 when the bars 17 are in thecontractedposition.

When the adjusting screw pin 11 is so positioned that the distancebetween the centers of the pin 8-8 and the distance between the pins20-2() are equal, then any movement of the links will impart parallelmotion to the carrier bars 17 towards and from the mandrel, the motion,of course, being a swinging motion through the medium of the links 21.

When it is desired to use the tapered holes the distance between thecenters of the pins 8 8 is varied accordingly by turning the adjustingscrew 11 to increase or diminish that distance as may be desired. Whenthe distance is increased the bars 17 will incline toward the end havingthe adjusting screw pin 11, whereas when the distance is decreased theinclination will be in the other direction.

In using my invention the abutment 16 is unscrewed and with the bars 17inthe contracted position the tool is placed in the hole to be honed.After the tool has been placed in the hole to be honed the abutmentmember 15 is screwed up to expand the bars 17 from the mandrel 1 andcause them to engage the wall of the hole, after which the abutment 16is replaced and screwed up tight. The tool is then ready to be chuckedinto the driving engine and placed under rotation. If it is desired toexpand the tool further in order to abrade deeper, the abutment 16 isslacked and the abutment 15 tightened correspondingly. If the hole is atapered hole,- as for instance the holes in wheel hubs for the aXleends, the adjusting pin llvis turned to permit the required inclinationof the bars 17 which are expanded into contact with the wall of the holeby tightening the abutment 15. The adjustment can then be made secure bytightening the abutment 16 against the adjacent ends of the bars 17.

From practical tests I find that I can cut the pin holes in the pistonsof internal combustion engines from standard to .010 in thirty seconds.vThis accomplishment has not been found possible by any of the tools nowon the market and known to me.

From the foregoing description, taken in connection with theaccompanying drawing,

it is thought the construction, operation and many advantages of myinvention over the tools of the prior art will be clear to those skilledin the art to which the invention appertains.

What I claim isz- 1. A hone of the character stated comprising a mandrelhaving threaded portions spaced apart, a threaded abutment member oneach of said threaded portions, abrasive carrier bars, sets of links andpivot pins for mounting said carrier bars on said mandrel, said threadedabutments arranged to abut the ends of said bars and adjust and securesaid bars in their adjusted positions, and abrasives carried by saidbars.

2. A hone of the character stated comprising a mandrel having threadedportions spaced apart, threaded abutment members on said threadedportions, abrasive carrier bars, sets of links and pivot pins formounting said carrier bars on said mandrel, said threaded abutmentsarranged to abut the ends of said bars and adjust and securesaid bars intheir adjusted positions, and abrasives carried by' said bars, saidabrasives including abrasive sustaining backs overlying-said bars withtheir longitudinal edges anchored to the longitudinal edges of saidcarrier bars.

3. A hone of the character stated comprising a mandrel having threadedportions spaced apat, a threaded abutment member moana' i on ea ih ofsaid threaded portions, abrasive ,carrier bars, sets of links and pivotpins for mounting said carried bars on said mandrel, said threadedabutments arranged to abut f the ends of said bars and adjust and secureand to the distance between the pivot pins 'connecting the links tothemandrel.

4. A hone of the character stated comprising a mandrel having threadedportions spaced apart, threaded abutment members 16 0n said threadedportions, abrasive carrier bars, sets of links and pivot pins formounting'said carrier bars on said mandrel, said threaded abutmentsarranged to abut the ends of said bars and adjust and secure said barsgo in their adjusted positions, and abrasives carried by said bars, saidabrasives including abrasive sustaining backs overlying said bars withtheir longitudinal edges anchored to the longitudinal edges of saidcarrier bars, the distance between the pivot pins connecting the linksto the carrier bars being equal to one another and to the distancebetween the givpt pins connecting the links to the manre f 5. A hone ofthe character stated comprising a mandrel having threaded portionsspaced apart. threaded abutment members on said threaded portions,abrasive carrier bars, sets of links and pivot pins for mounting saidcarrier bars on said mandrel, said threaded abutments arranged to abutthe endsof said bars and adjust and secure said bars in their adjustedpositions, and abrasives carried by said bars, said abrasivesl includingabrasive sustaining backs overlying said bars with their longitudinaledges anchored. to the longitudinal edges of said carrier bars, thedistance between the pivot pins connecting the links to the carrier barsbeing equal to one another and to the distance between the pivot pinsconnecting the links to the mandrel, the ivot pins connecting the linksto the carrier ars being fixed as to their relative positions, at leastone of the pivot pins connecting the links to the mandrel beingadjustable toward and from the other to vary the distance between thesame, and means to hold said ad-` f bars in their adjusted posltionrs,and abrasivcs carried by said bars, the distance between the pivot pinsconnecting the links to the carrier bars being equal toone mother and to.the distance vbetween the pivot pins connecting the links to themandrel, the pivot ins connecting the links to the carrier bars ingfixed as to their relative positions, at least one of the pivot pinsconnectingthe Y links lto the mandrelbeing ad'ustable toward and fromthe other to vary e distance beltween-the same, and means to hold saidadjustable pin when once adjusted against accidental displacement.

7. A hone of the character statedcomprising a mandrel having1 threadedportions spaced lapart, threaded abutment members on said threadedportions, abrasive carrier bars, sets of links and pivot pins formounting said carrier bars on said mandrel, said threaded abutmentsarranged to abut the ends of said bars and adjust and secure said barsin their adjusted positions, and abrasives carried b said bars, saidabrasives including abraslve sustainin backs overlying said bars withtheir longitudinal edges anchored to the longitudinal edges of saidcarrier bars, the distance between the pivot pins connecting the linksto the carrier bars bein equal to one another and to the distance tweenythe pivot ypins' con.

necting the links to the mandrel, the pivot pins connecting the links tothe carrier bars eing fixed as to their relative positions, at

least one of 'the pivot pins connecting the links to the mandrel beingadjustable toward and from the other to vary the distance between thesame, and mea-ns for moving said adjustable pin throughout its range of.adv justment. J

8. A hone of the character stated comprising a mandrel having 4threadedportions spaced apart, a threaded abutment member on each of saidthreaded portions, abrasive carrier bars, sets of links and pivot pinsfor mounting said carrier bars on said mandrel, said threaded abutmentsarranged to abut the ends of said bars and adjust and secure said barsin their adjusted positions, and abrasives carried by said bars, thedistance between the pivot pins connecting the links to the carrier barsbeing equal to one another and to the distance between the pivot pinsconnecting the links to the mandrel, the pivot pins connecting the linksto the carrier bars being fixed as to position, at

least one of the 'pivot pins connecting the links to the mandrel beingadjustable toward and from the other to vary the distance between thesame, and means for moving said .adjustable -pin throughout its range ofad` justment.

9. Alhone of the character stated comprising a mandrel having threadedportions spaced apart, threaded abutment ymembers on said threadedportions, abrasive carrier bars, sets of links and pivot pins formounting said carrier bars on lsaid mandrel, said threaded abutmentsarranged to abut the ends of said bars and adjust and secure said barsin their adjusted positionsand abrasives carried by said bars, saidabrasives including abrasive sustaining backs overlying said bars withtheir longitudinal edges anchored to the longitudinal edges of saidcarrier bars, the distance between the pivot pms Connecting-the--linkstothe carrier barsfb'e ing equal to one another and to thedistancebetween the pivot pins connecting the llnks to the mandrel, the pivotpins Aconnecting the links to the carrier bars being fixed as to theirrelative positions, at least one of the pivot pins connecting the linksto the mandrel being adjustable toward and from .the other to Vary thedistance between the same, and means for moving said adjustable' pinthroughout its range of adjustment and holding said adjustable pin inits adjusted pos1 tions.

10. A hone of the character stated comprising a mandrel having threadedportions spaced apart, a threaded abutment member on each of saidthreaded portions, abrasive carrier bars, sets of links and pivot pinsfor mounting said carrier bars on said mandrel, said threaded abutmentsarranged to abut the ends of said bars and adjust and secure said barsintheir adjusted positions, and abrasives carried by said bars, thedistance between the pivot pins connecting the links to the carrier barsbeing equal to one another vand to the distance between the pivot pinsconnecting the links to the mandrel, the pivot pins connecting the linksto the carrier bars being fixed as to their relative positions, at leastone of the pivot pins connecting the links to the mandrel beingadjustable toward and from the other to vary the distance between thesame, and means for moving said adjustable pin throughout its range ofadjustment and holding said adjustable pin in its adjusted positions.

1:1. A hone of the character stated comprising a mandrel having.threaded portions spaced a art, threaded abutment members on said treaded portions, abrasive carrier bars, sets of links and pivot pins formount` ing said carrier bars on said mandrel, said threaded abutmentsarranged to abut the ends of said bars and adjust and secure said barsin their adjusted ositions, and abraars, said abrasives includingabrasive sustaining, backs overlying said bars with their longitudinaledges on said threaded portions, labrasive 'carrier bars, sets of linksyfor "connecting the respective carrier bars directly to said man# drel,pivot pins connecting said links to the respective carrier bars, pivotpins passing through aperturesin said mandrel to each of which a pair oflinks is pivoted, said threaded abutments arranged to abut therespective ends of said bars and adjust and secure said bars in theiradjusted positions, and abrasives carried bysaid bars.

13. A hone of the character stated comprising a mandrel having threadedportions spaced a art, threaded abutment members on said t readedportions, abrasive carrier bars, sets of links for connecting therespective carrier bars'directly to saidmandrel, plvot pms connectingsaid links to the respective carrier bars, pivot pins passing throughapertures in said mandrel to eacho which a pair of links is pivoted,said threaded abutments arranged to abut the respective ends of saidbars and adjust and secure said bars in their adjusted positions, andabrasives carried by said bars, one of the pivot pins connecting a pairof links to the mandrel'having movement in the direction of the axis ofthe mandrel and means carried by the mandrel for eil'ecting suchmovement for the purposes described.

WILLIAM PAUL ROBERTS.

anchored to the longitudinal edges of said j carrier bars, the distancebetween the pivot pins connecting. the links to the carrier bars beingequal to one another and to the distance between the pivot pinsconnecting the links to the mandrel, the pivot pins connecting the linksto the carrier bars being fixed as to their relative positions, at leastone of the pivot pins connecting the links to the mandrel be- IOL

